With the advance in video and audio processing technologies, the production of high-definition, high-quality content has increased. Users, who in the past have demanded high-definition, high-quality content, desire realistic images and sound, and thus, extensive research has been conducted to provide 3D images and 3D sound.
A 3D sound technology enables a user to sense space by arranging a plurality of speakers at different positions on a horizontal plane and outputting the same sound signal or different sound signals through the speakers. However, an actual sound may be generated from different positions on a horizontal plane and may also be generated at different elevations. Therefore, there is a need for a technology that reproduces sound signals generated at different elevations through speakers arranged on a horizontal plane.